Intimately Bonded 2D Materials and Responsive Polymer Brushes for Adaptive Nanocomposites

Abstract To develop next-generation adaptive and functional nanocomposites, it is important to utilize new types of functional nanomaterials such as 2D layered materials (2DLMs), as well as functional polymers such as those with stimuli-responsive properties. However, it is still challenging to integrate 2DLMs and responsive polymers in a precise and well-controlled way without any segregation or phase separation. Here, we developed a new method to attach temperature responsive polymers to the surface of 2DLMs through an ultrathin intermediate polydopamine layer. This new surface functionalization strategy enables all the individual 2DLM nanosheets to be uniformly grafted with the responsive polymer brushes, so that nanocomposites with well-ordered internal structure can be fabricated through a simple one-step assembly. Small angle neutron scattering (SANS) was used as the major tool to investigate the molecular structure, as well as intermolecular assembly of the hybrid nanosheets at different conditions. The hybrid ultrathin nanosheets show distinct temperature responsive behaviors, which is also dependent on the thickness and chemistry of the 2DLMs. The nanocomposite membranes based on one-step assembly of the hybrid nanosheets show tunable mechanical properties and well-defined internal structure.